Is it possible to make a launcher within a panel wider?

I have one panel with one launcher. The launcher contains four applications at the moment: Firefox, Geany, Terminal, Calculator.

However, only the first one, Firefox, is shown; to start any of the other applications, I first need to click the little down-pointing triangle, this expands the launcher, and then I move down and can select the desired app.

What I want to do, is to make the launcher wider so that all applications are shown and directly selectable (there is plenty of free space in the panel). Is this possible, and if yes, how?